RT9055 - Richtek

®
RT9055
300mA Dual LDO Regulator
General Description
Features
The RT9055 is a dual channel, low noise, and low dropout
regulator sourcing up to 300mA at each channel. The output
voltage range is from 0.9V to 3.5V with an input voltage
range from 1.5V to 5.5V.

Wide Operating Voltage Range : 1.5V to 5.5V

Low Noise for RF Application
No Noise Bypass Capacitor Required
Fast Response in Line/Load Transient
TTL Logic Controlled Shutdown Input
Low Temperature Coefficient
Dual LDO Outputs (300mA/300mA)
Ultra-Low Quiescent Current : 29μ
μA/LDO
High Output Accuracy 2%
Short Current Protection
Thermal Shutdown Protection
Current Limit Protection
Short Circuit Thermal Folded Back Protection
RoHS Compliant and Halogen Free
The RT9055 offers 2% accuracy, extremely low dropout
voltage and extremely low quiescent current (only 29μA
per LDO). The shutdown current is near zero which is
suitable for battery powered applications. The RT9055 also
provides protection functions such as current limiting,
output short circuit protection, and over temperature
protection.


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
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The RT9055 allows stable operation with very small
ceramic output capacitors, hence minimizing required
board space and component cost.
The RT9055 is available in a WL-CSP-6B 0.8x1.2 package.


Applications

Ordering Information

RT9055-

Cellular Handsets
Battery Powered Equipment
Hand-Held Instruments
Portable Information Appliances
Package Type
WSC : WL-CSP-6B 0.8x1.2

Output Voltage : VOUT1/VOUT2
VOUT2 > VOUT1 is Recommended
Pin Configurations
(TOP VIEW)
Note :
EN1 A1
Richtek products are :


RoHS compliant and compatible with the current require-
GND
B1
ments of IPC/JEDEC J-STD-020.
EN2
C1
Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
DS9055-02 August 2014
A2
VOUT1
B2
VIN
C2
VOUT2
WSC-CSP-6B 0.8x1.2
Available Voltage Version
Code
A
D
G
K
N
R
V
Y
2
Voltage Code Voltage
3.5
1.85
1.8
2.6
2.85
3.2
2.9
1.9
1.1
B
E
H
L
P
S
W
U
3
1.3
2.1
2
2.7
3
3.3
1.6
1.4
1
Code Voltage
C
F
J
M
Q
T
X
Z
1.2
1.5
2.5
2.8
3.1
2.65
3.15
1.25
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1
RT9055
Typical Application Circuit
B2
VIN
CIN
1µF
A1
Chip Enable
C1
VOUT1
VIN
A2
COUT1
1µF
RT9055
EN1
VOUT2
C2
COUT2
1µF
EN2
VOUT1
VOUT2
GND
B1
Functional Pin Description
Pin No.
Pin Name
Pin Function
A1
EN1
LDO1 Enable (Active High).
A2
VOUT1
LDO1 Output Voltage.
B1
GND
Ground.
B2
VIN
Supply Input.
C1
EN2
LDO2 Enable (Active High).
C2
VOUT2
LDO2 Output Voltage.
Function Block Diagram
EN1
Shutdown
and
Logic Control
13µA
Output
Driver
-
VREF
VIN
+
VOUT1
Current Limit
and
Thermal Protection
EN2
Shutdown
and
Logic Control
13µA
-
VREF
+
Output
Driver
VOUT2
GND
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
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2
Current Limit
and
Thermal Protection
is a registered trademark of Richtek Technology Corporation.
DS9055-02 August 2014
RT9055
Absolute Maximum Ratings








(Note 1)
Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------Other I/O Pins Voltages ------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
WL-CSP-6B 0.8x1.2 -----------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
WL-CSP-6B 0.8x1.2, θJA -----------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Model) ---------------------------------------------------------------------------------------------MM (Machine Model) -----------------------------------------------------------------------------------------------------
Recommended Operating Conditions



−0.3V to 6V
−0.3V to 6V
0.670W
148°C/W
260°C
150°C
−65°C to 150°C
2kV
200V
(Note 4)
Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------- 1.5V to 5.5V
Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VIN = VOUT + 1V, CIN = COUT = 1μF, TA = −40°C to 85°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
VOUT = 1.2V to 1.4V, IOUT = 300mA
50
--
550
VOUT = 1.5V to 2.4V, IOUT = 300mA
40
--
400
VOUT = 2.5V to 3.5V, IOUT = 300mA
20
--
300
0.9
--
3.5
V
Input Power Supply
Dropout Voltage
(Note 5)
VDROP
mV
Output Voltage Range
VOUT
VOUT Accuracy
V
IOUT = 1mA to 300mA
2
--
2
%
Line Regulation
VLINE
VIN = (VOUT + 1) to 5.5V, IOUT = 1mA
2
--
2
%
Load Regulation
VLOAD
1mA < IOUT < 300mA
1.5
--
1.5
%
Current Limit
ILIM
RLOAD = 0
350
600
--
mA
Quiescent Current
IQ
VEN > 1.5V
--
58
--
A
Shutdown Current
ISHDN
VEN < 0.4V
--
--
1
A
EN Input
Logic-High
Threshold
Logic-Low
Voltage
VOUT Discharge Resistance
in Shutdown
(Note 6)
VIH
VIN = 2.5V to 5.5V, Power On
1.2
--
--
VIL
VIN = 2.5V to 5.5V, Shutdown
--
--
0.4
VIN = 5V, EN1 = EN2 = GND
--
3
--
k
EN Pull Low Current
IEN
8
13
18
A
Thermal Shutdown
TSD
--
170
--
°C
Thermal Shutdown
Hysteresis
TSD
--
40
--
°C
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
DS9055-02 August 2014
V
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3
RT9055
Parameter
Symbol
Test Conditions
Min
Typ
Max
--
70
--
--
70
--
--
70
--
f = 100kHz, VIN =VOUT + 1V,
COUT = 2.2F, ILOAD = 50mA
--
54
--
f = 200kHz, VIN = VOUT + 1V,
COUT = 2.2F, ILOAD = 50mA
--
45
--
f = 300kHz, VIN = VOUT + 1V,
COUT = 2.2F, ILOAD = 50mA
--
38
--
COUT1 = COUT2 = 10F, 10Hz
to100kHz, IOUT1 = IOUT2 = 1mA
--
100
--
f = 100Hz, VIN = VOUT + 1V,
COUT = 2.2F, ILOAD = 50mA
Power Supply Rejection
Ratio
PSRR
Output Voltage Noise
f = 1kHz, VIN = VOUT + 1V,
COUT = 2.2F, ILOAD = 50mA
f = 10kHz, VIN = VOUT + 1V,
COUT = 2.2F, ILOAD = 50mA
Unit
dB
VRMS
Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in
the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may
affect device reliability.
Note 2. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. The CSP
balls connect directly to the internal GND copper plane by 2 vias, the via diameter is about 1mm.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. The dropout voltage is defined as VIN − VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
Note 6. It is guaranteed by design.
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is a registered trademark of Richtek Technology Corporation.
DS9055-02 August 2014
RT9055
Typical Operating Characteristics
Output Voltage vs. Temperature
Quiescent Current vs. Temperature
1.22
80
1.21
70
Quiescent Current (µA)
Output Voltage (V)
1.20
1.19
1.18
1.17
1.16
1.15
1.14
1.13
VIN = 3.7V, No Load
1.12
60
50
40
30
20
10
VIN = 3.7V, No Load
0
-50
-25
0
25
50
75
100
125
-50
-25
0
25
50
75
100
Temperature (°C)
Temperature (°C)
Dropout Voltage vs. Load Current
Line Transient Response
125
140
Dropout Voltage (mV)
120
125°C
100
25°C
VIN
(2V/Div)
80
−40°C
60
VOUT
(20mV/Div)
40
20
VOUT = 3.3V
VIN = 2.8V to 4.2V, ILOAD = 1mA
0
0
50
100
150
200
250
Time (100μs/Div)
300
Load Current (mA)
Line Transient Response
Line Transient Response
VIN
(2V/Div)
VIN
(2V/Div)
VOUT
(20mV/Div)
VOUT
(20mV/Div)
VIN = 2.8V to 4.2V, ILOAD = 10mA
Time (100μs/Div)
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
DS9055-02 August 2014
VIN = 2.8V to 4.2V, ILOAD = 100mA
Time (100μs/Div)
is a registered trademark of Richtek Technology Corporation.
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RT9055
Load Transient Response
Line Transient Response
VOUT1
(50mV/Div)
VIN
(2V/Div)
IOUT
(100mA/Div)
VOUT
(20mV/Div)
VIN = 2.8V to 4.2V, ILOAD = 300mA
VIN = 1.8V, ILOAD = 1mA to 100mA
Time (100μs/Div)
Time (250μs/Div)
Load Transient Response
Power On from EN
VOUT1
(50mV/Div)
VEN
(1V/Div)
VOUT1
(1V/Div)
IOUT
(100mA/Div)
VOUT2
(1V/Div)
VIN = 1.8V, ILOAD = 1mA to 300mA
VIN = 3.6V, VEN = 2V
VOUT1 = VOUT2 = 1.2V, IOUT1 = IOUT2 = 100mA
Time (250μs/Div)
Time (50μs/Div)
Power Off from EN
VOUT1 Noise
VEN
(1V/Div)
VOUT
(100μV/Div)
VOUT1
(1V/Div)
VOUT2
(1V/Div)
VIN = 3.6V, VEN = 2V
VOUT1 = VOUT2 = 1.2V, IOUT1 = IOUT2 = 100mA
Time (50μs/Div)
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VIN = VEN = 4.5V, ILOAD = 1mA
Time (5ms/Div)
is a registered trademark of Richtek Technology Corporation.
DS9055-02 August 2014
RT9055
PSRR
VOUT2 Noise
0
-10
PSRR (dB)
-20
VOUT
(100μV/Div)
-30
-40
-50
-60
VOUT = 1.2V
VIN = VEN = 4.5V, ILOAD = 1mA
-70
Time (5ms/Div)
10
10
100
100
1K
1000
10K
10000
100K
100000
1M
1000000
(Hz)
Frequency (Hz)
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
DS9055-02 August 2014
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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RT9055
Applications Information
The output capacitor must meet both requirements for
minimum amount of capacitance and ESR in all LDOs
application. The RT9055 is designed specifically to work
with low ESR ceramic output capacitor in space-saving
and performance consideration. Using a ceramic capacitor
whose value is at least 1μF with ESR is > 20mΩ on the
RT9055 output ensures stability. The RT9055 still works
well with output capacitor of other types due to the wide
stable ESR range. Figure 1 shows the curves of allowable
ESR range as a function of load current for various output
capacitor values. Output capacitor of larger capacitance
can reduce noise and improve load transient response,
stability, and PSRR. The output capacitor should be located
not more than 0.5 inch from the VOUT pin of the RT9055
and returned to a clean analog ground.
Region of Stable COUT ESR vs. Load Current
Region of
of Stable
StableCCOUT
ESR(Ω)
(Ω)
Region
OUTESR
100
VIN = 5V, CIN = COUT1 =COUT2 =1μF/X7R
10
Unstable Region
1
Stable Region
0.1
0.01
Simulation Verify
Thermal Considerations
For continuous operation, do not exceed absolute
maximum junction temperature. The maximum power
dissipation depends on the thermal resistance of the IC
package, PCB layout, rate of surrounding airflow, and
difference between junction and ambient temperature. The
maximum power dissipation can be calculated by the
following formula :
PD(MAX) = (TJ(MAX) − TA) / θJA
where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJA is the junction to ambient
thermal resistance.
For recommended operating condition specifications, the
maximum junction temperature is 125°C. For WL-CSP6B 0.8x1.2 package, the thermal resistance, θJA, is 148°C/
W on a standard JEDEC 51-7 four-layer thermal test board.
The maximum power dissipation at TA = 25°C can be
calculated by the following formula :
P D(MAX) = (125°C − 25°C) / (148°C/W) = 0.670W
for WL-CSP-6B 0.8x1.2 package
The maximum power dissipation depends on the operating
ambient temperature for fixed T J (MAX) and thermal
resistance, θJA. The derating curves in Figure 2 allow the
designer to see the effect of rising ambient temperature
on the maximum power dissipation.
Maximum Power Dissipation (W)1
Like any low-dropout regulator, the external capacitors used
with the RT9055 must be carefully selected for regulator
stability and performance. Using a capacitor whose value
is >1μF on the RT9055 input and the amount of capacitance
can be increased without limit. The input capacitor must
be located a distance of not more than 0.5 inch from the
input pin of the IC and returned to a clean analog ground.
Any good quality ceramic or tantalum can be used for this
capacitor. The capacitor with larger value and lower ESR
(equivalent series resistance) provides better PSRR and
line-transient response.
0.8
Four-Layer PCB
0.6
0.4
0.2
0.0
0
0.001
0
50
100
150
200
250
Load Current (mA)
300
25
50
75
100
125
Ambient Temperature (°C)
Figure 2. Derating Curve of Maximum Power Dissipation
Figure 1. Stable COUT ESR Range
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is a registered trademark of Richtek Technology Corporation.
DS9055-02 August 2014
RT9055
Outline Dimension
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min.
Max.
Min.
Max.
A
0.500
0.600
0.020
0.024
A1
0.170
0.230
0.007
0.009
b
0.240
0.300
0.009
0.012
D
1.150
1.250
0.045
0.049
D1
E
0.800
0.750
0.031
0.850
0.030
0.033
E1
0.400
0.016
e
0.400
0.016
6B WL-CSP 0.8x1.2 Package (BSC)
Richtek Technology Corporation
14F, No. 8, Tai Yuen 1st Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.
DS9055-02 August 2014
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9